Loading dbf files now verifies expected encoded byte size versus actual.

Includes applying footer byte only if one is not found in cached dataStore.

godbf/dbfio.go

@@ -34,10 +34,23 @@ func createDbfTable(s []byte, fileEncoding string) (table *DbfTable, err error)
 		return nil, fieldErr
 	}
 
+	if verifyErr := verifyHeaderAgainstByteArray(s, dt); verifyErr != nil {
+		return nil, verifyErr
+	}
+
 	finaliseSchema(s, dt)
 	return dt, nil
 }
 
+func verifyHeaderAgainstByteArray(s []byte, dt *DbfTable) error {
+	expectedSize := uint32(dt.numberOfBytesInHeader) + dt.numberOfRecords*uint32(dt.lengthOfEachRecord) + 1
+	actualSize := uint32(len(s))
+	if actualSize != expectedSize {
+		return fmt.Errorf("encoded content is %d bytes, but header expected %d", actualSize, expectedSize)
+	}
+	return nil
+}
+
 func finaliseSchema(s []byte, dt *DbfTable) {
 	dt.dataEntryStarted = true // Schema changes no longer permitted
 	dt.dataStore = s           // TODO: Deprecate?
@@ -148,7 +161,7 @@ func writeContent(dt *DbfTable, f *os.File) error {
 	if dsErr := writeDataStore(dt, f); dsErr != nil {
 		return dsErr
 	}
-	if footerErr := writeFooter(f); footerErr != nil {
+	if footerErr := writeFooter(dt, f); footerErr != nil {
 		return footerErr
 	}
 	return nil
@@ -163,8 +176,14 @@ func writeDataStore(dt *DbfTable, f *os.File) error {
 
 const EofMarker byte = 0x1A
 
-func writeFooter(f *os.File) error {
+func writeFooter(dt *DbfTable, f *os.File) error {
 	eofBytes := []byte{EofMarker}
+
+	dataStoreLength := len(dt.dataStore)
+	if dt.dataStore[dataStoreLength-1] == EofMarker {
+		return nil
+	}
+
 	if _, footerErr := f.Write(eofBytes); footerErr != nil {
 		return footerErr
 	}

godbf/dbfio_test.go

@@ -10,6 +10,8 @@ import (
 )
 
 const validTestFile = "testdata/validFile.dbf"
+const lessThanActualRecordsFile = "testdata/lessThanActualRecords.dbf"
+
 const realFile = "testdata/122016B1.DBF"
 
 // For reference: https://en.wikipedia.org/wiki/.dbf#File_format_of_Level_5_DOS_dBASE
@@ -88,6 +90,15 @@ func TestDbfTable_EndOfFieldMarkerMissing_TableParsingError(t *testing.T) {
 	g.Expect(byteArrayErr.Error()).To(ContainSubstring("end-of-field marker missing"))
 }
 
+func TestDbfTable_NewFromLessThanActualRecords_Errors(t *testing.T) {
+	g := NewGomegaWithT(t)
+
+	_, readError := NewFromFile(lessThanActualRecordsFile, testEncoding)
+
+	g.Expect(readError).ToNot(BeNil())
+	t.Log(readError)
+}
+
 func verifyTableIsCorrect(tableUnderTest *DbfTable, g *GomegaWithT) {
 	verifyFieldDescriptorsAreCorrect(tableUnderTest, g)
 	verifyRecordsAreCorrect(tableUnderTest, g)